Avoid lint warnings.

Author: kevinpschaaf

lib/elements/dom-if.js

@@ -268,6 +268,9 @@ class DomIfBase extends PolymerElement {
     }
   }
 
+  // Ideally these would be annotated as abstract methods in an abstract class,
+  // but closure compiler is finnicky
+  /* eslint-disable valid-jsdoc */
   /**
    * Abstract API to be implemented by subclass: Returns true if a template
    * instance has been created and inserted.
@@ -295,7 +298,7 @@ class DomIfBase extends PolymerElement {
    * @param {Node} parentNode The parent node to insert the instance into
    * @return {void}
    */
-  __createAndInsertInstance(parentNode) { }
+  __createAndInsertInstance(parentNode) { } // eslint-disable-line no-unused-vars
 
   /**
    * Abstract API to be implemented by subclass: Removes nodes created by an
@@ -315,6 +318,7 @@ class DomIfBase extends PolymerElement {
    * @return {void}
    */
   _showHideChildren() { }
+  /* eslint-enable valid-jsdoc */
 }
 
 /**